To facilitate recognition of the arrangement of keys by detecting that a portable terminal is separated from the body according to an electric field level difference, when disconnecting a call in an environment where the light is insufficient.

A portable terminal 101 detects that the surrounding is put in a dark state by a light-receiving part 108; and when the light of a key or a display part is turned off during a conversation, detects the state in which the portable terminal is separated from the body, based on an electric field level difference by a control part 103, and turns on a light 105 for a key part and a light 107 for a display part, in order to perform key operation during conversation, or to confirm the information of a display part.