The results of the development and studies on the focal plane array (FPA) of the format 320x240 on the PtSi basis have been presented. The development has been executed based on the CMOS technology. The spectral range is 3 - 5 µm. The main frame frequency is 25 Hz. It has been shown that FPA posses the possibility of regulating the time of the current accumulation at fixed frame frequency and the possibility of subtracting the background forming constant in the output device.