PURPOSE: To make switching with a proper depression sensitivity possible, by absorbing the variance for applied pressure of an external member such as a button, the variance of a resistance for applied pressure of a pressure sensitive conductive rubber, etc.

CONSTITUTION: Resistances R50, R60, and R70 are connected in series with a pressure sensitive conductive rubber 12, and they are selected by clock signals CL40, CL50 and CL60 respectively. Clock signals CL10∼CL30 to determine one input voltage Va of a voltage comparing circuit 13 turn on transistors T10∼T30 to determine the input voltage. The signal compared by clock signals CL10∼CL40 is read into D type flip flops F90, F80, and F70 of the first latch circuit successively by clock signals CL150∼CL140 and CL130 and is outputted to respective Q outputs. The second latch circuit 3 controls the function, by which output data of the first latch circuit 22 is latched again, and a gate circuit which outputs pressure detection data.