To provide an electrical device preventing accidents caused by deterioration occurring due to long term use.

An electrical device 1A having a main body function part 2 operated by power supplied from an external power source 7, has: a power supply cable 3; an energization blocking part 10 setting a power supply path from the external power source 7 to the main body function part 2 via the power supply cable 3 to be in one of an energization possible state and a blocking state; and a lapse period measuring part 20 driven by a built-in battery 23. The lapse period measuring part 20 has a timer 21 measuring a lapse time from the time when the electrical device 1A is manufactured, and a controller 22 controlling the energization blocking part 10. The timer 21 transmits an alert signal to the controller 22 when the measured lapse time reaches a design limit period for the electrical device 1A. The controller 22 sets the energization blocking part 10 to be in the energization possible state until it receives the alert signal is received, and sets the energization blocking part 10 to be in the blocking state when it receives the alert signal.