A biological information detection device has a device main body and a biological signal detection portion formed integrally with the device main body. The detection portion has at least one electrode for contacting a biological surface of a human body. A mounting portion mounts the main body and the detection portion to a human body without the mounting portion being directly attached to the detection portion. The main body and the detection portion are integrally connected by a mechanical connection portion that mechanically connects the main body and the detection portion to each other, and by an electrical connection portion that electrically connects the main body and the electrode of the detection portion to each other. The mechanical connection portion and the electrical connection portion are positioned relative one another so as not to be arranged alongside a load direction of an external force acting on the mechanical connection portion.