PURPOSE: To provide an output circuit which can be simply constituted by increasing the charge amount which can be treated by a picture element of a two dimensional infrared rays detector.

CONSTITUTION: Charge input (q) is inputted to an integrator 2 via a switch 1. Charge accumulated in a capacitance 22 of the integrator 2 is inputted to a comparator 5 and compared with a specified potential, and a judgment signal is obtained. The judgment signal is inputted to a control circuit 4, and discharging accumulated charge is discharged by the switch. A counter 6 counts the number of times of discharge, and the counted value is made the output of a detector.