PROBLEM TO BE SOLVED: To provide a biological information detection device capable of detecting a heart rate or respiration after reducing the effects of displacement, etc. of a living body surface derived from factors other than the heart rate or respiration.SOLUTION: The biological information detection device is arranged in an apparatus having a body contact surface in contact with a portion of the body and detects biological information of the user of the apparatus, and comprises: a detection unit 10 including a projection part for projecting radio waves toward a portion of the body and a receiving part for receiving reflection of radio waves projected by the projection part； a seat 20 for mounting the detection unit thereon； and distance keeping parts one end of which is fixed to the seat and the other end of which has a contact portion 31 in contact with a surface opposite the body contact surface.SELECTED DRAWING: Figure 1
