Kazimierz Gayczak (1872-1933), MSc Eng, the founder and co-owner of ERA factory, graduated from the Darmstadt University of Technology. He was the chairman of the Polish Association of Power Stations, a member of the National Electrical Council and many industrial associations. He was the exponent of the opinion of many eminent experts who claimed that a company would not be granted a monopoly on the supplies of electrical equipment for the Polish Railways (PKP) until a complex task of controlling the voltage of electric generators fitted in railway cars was handled properly. The voltage in generators should be adjusted to the speed of the train so that when coupled with batteries they could ensure a steady intensity of lighting.

Thanks to international cooperation initiated by Polish entrepreneurs, who understood that the development of railways would require continuous supplies of electrical appliances, Polskie Zakłady Elektrotechniczne Sp. Akc. [Polish Electrical Engineering Plant, joint-stock company] was founded. ERA, a Czech company, proved the most important partner in those days. ERA held patents developed by its Chief Engineer A. Junek, which were of interest to Polish railway industry. The company's name is derived from first letters of Czech words: Elektrotechnicki Regulator Automaticky, defining the primary speciality of the Prague factory.

In Poland, a Polish-Czech mixed-capital company, with a slight majority held by the Czech group, was established. Following the construction of manufacturing facilities in Włochy (part of Warsaw), the production was started in 1927. Basic manufacture included electric generators, automatic control units and other accessories for mobile lighting installations fitted on rail cars, locomotives, ships and airplanes. In 1930s the factory began to produce armaments.

In 1932 a licence was bought from Norma, a company from Vienna. Increasing numbers of board-mounted and laboratory voltmeters and ammeters as well as multi-purpose testers and induction coils were produced. During the Nazi occupation patents held by Norma for measuring instruments were replaced by Siemens’ licence. Siemens’ Berlin headquarters assumed supervision over ERA.

The factory was nationalized in 1948. It was officially named Zakłady Wytwórcze Przyrządów Pomiarowych im. Janka Krasickiego [Janek Krasicki Measuring Instruments Manufacturing Plant]. In 1957-68, ninety-nine new products were introduced into production. The program included laboratory and accuracy class 0.2 – 0.5 – 1.0 portable meters, insulation and earth-insulation testers, technical and laboratory bridges, compensators, galvanometers, battery cell testers. All of those demanding high-precision instruments were painstakingly designed by the in-house design office. Assessment of assumptions, consultancy and prototype testing were contracted to the Institute of Technology or the Industrial Institute of Automatics and Measurements.

At the beginning of the year 1970, an external branch of Z.W.P.P ERA specializing in mechanics and horology was opened at the southwest edge of Gostynin. In mid-1971 the production of car flashers was moved from the main factory to the Gostynin branch. Later on, the same happened to the assembly of MER 72 TM and MER 96 TM miniature meters for use at sea and in tropical climate. In 1972 the construction of a new manufacturing plant in the suburbs of Gostynin in Płocka Street was finalized. The automotive flasher branch was joined to the new plant. This plant served as basic manufacturing facility for the measuring instruments industry. It manufactured various components and sub-assembles for meters and mini-gauges.

Due to transformations in the political system of Poland after 1989, many nationalised Polish companies were faced with a new, difficult reality of free market. As a consequence many companies went bankrupt. Sadly, the ERA factory in Warsaw failed to stand the test of surviving on the free market. At the turn of the century the factory was reorganised, as a result of which in 2002 a new company – Przedsiębiorstwo Wielobranżowe ERA-GOST Sp. z o. o. [ERA-GOST Multitrade Enterprise, limited liability company] – was established in the Gostynin branch. The company continues to manufacture analogue and digital measuring instruments using ERA’s extensive expertise.

In February 2007 the company was renamed as ERA-GOST Sp. z o.o.