Portable electronic device and control method

A portable electronic device (1) according to one embodiment is equipped with: a first sensor (5) for detecting proximity to the device; a second sensor (16) for detecting a biological reaction; and a control unit (10) for determining that the device is in a storage unit provided in clothing, when the first sensor (5) detects proximity to the device and the second sensor (16) detects a biological reaction. As a result, the portable electronic device (1) according to one embodiment is capable of detecting a state where the device is in the storage unit of clothing, as a state of placement of the portable electronic device (1).