A biological information measurement device according to the present invention detects a signal expressing biological information from a fingertip using an internal sensor (S1). A first perfusion index and first biological information aside from the first perfusion index are obtained from the signal detected by the internal sensor (S2, S3). It is determined whether or not the first perfusion index is greater than or equal to a first threshold (S4). When the first perfusion index is greater than or equal to the first threshold, the first biological information is permitted to be displayed in a display unit (S5). However, when the first perfusion index is less than the first threshold, a notification is made indicating that an external sensor that is lighter than a main body, is an entity separate from the main body, and is communicably connected to the main body is to be used (S6).