A biological information detection device includes a main body portion, a heartbeat detection portion, provided integrally with the main body portion, which has electrodes that come into contact with a biological surface, and a fixing band, detachably provided to the main body portion, which mounts the main body portion and the heartbeat detection portion to a human body. The main body portion and the heartbeat detection portion are integrally provided through a mechanical connection convex portion that mechanically connects the main body portion and the heartbeat detection portion to each other, and an electrical connection portion that electrically connect the main body portion and the electrodes of the heartbeat detection portion. A relative positional relationship between the mechanical connection convex portion and the electrical connection portion is set so as not to be arranged alongside a load direction of external force acting on the mechanical connection convex portion.
