To provide portable equipment which has a simple connection system between its main body and a power unit and can avoid connection in condition that mutually incompatible power is inputted, and enables a maintenance worker to know in what state of power supply the equipment body was used.

This portable information terminal (PDA)100 (portable equipment) is equipped with an A/D converter 22 which can measure the magnitude of DC voltage supplied to the main body 10 of equipment, a ROM 23 which stores that the supply state of DC voltage is abnormal, and a controller 21. The controller 21 is so constituted as to decide that the supply state of DC voltage is abnormal in case that the measured value of the DC voltage is outside the tolerable range of DC voltage supplied to the main body 10 of the equipment, and to allow the ROM23 to memorize that the supply state of the DC voltage is abnormal. It places the main body 10 of the equipment in a usable state if the number of times of making the ROM23 memorize that the supply state of the DC voltage is abnormal reaches 2.