PURPOSE: To easily test a console panel which has various key arrangements by providing a table stored with ket information corresponding to a key number on the maximum package of the console panel, and collating the key information with key information which corresponds to a key.

CONSTITUTION: When a key 1 is pressed, a key depression detecting circuit 4 detects the key depression and information on the key depression is inputted to a CPU5. The CPU5 accesses a table 6 in a memory 7 to load information 8 on the depressed key in the table 6, thereby making a check by comparison according to a program in the CPU5. Namely, key numbers Aij of various keys 1 arranged on the console panel in maximum key package are given teo the respective keys 1 in the form of absolute values, and the tape 6 containing respective pieces of key information corresponding to the key numbers Aij is stored in the memory 7. Then, the order of key depression is determined and those pieces of key information stored in the table 6 in the order are collated with pieces of pressed key information.