To calculate the sum of squares with high precision by performing squaring operation by performing two-stage voltage-time conversion for the same voltage and adding squaring operation results by an adding circuit which has capacity connection.

The analog computer element is equipped with squaring circuits SQ1 and SQ2 corresponding to analog input voltages X and Y, and those squaring circuits calculate the square X2 of the voltage X and the square Y2 of the voltage Y. Those calculation outputs are inputted to the adding circuit ADD, which adds them to generate a square sum output X2+Y2. Here, the squaring circuit SQ1 is equipped with 1st and 2nd threshold circuits which have inputted the 1st input voltage in common, a 1st timer is connected to the 1st threshold circuit, and a start signal having a specific voltage is inputted to the timer. Further, a 2nd timer is connected to the input of the 2nd threshold circuit, a signal corresponding to the output of the 1st threshold circuit is inputted to this timer, and the source voltage of a semiconductor integrated circuit is varied.