Non-contact biological sensors 1, 2 that detect biological information of a person by electromagnetic waves are provided in a seat 10 on which the person sits. The biological sensors 1, 2 are disposed in the seat 10 at positions away from members A1, A2, A3 (22, 32) which are the members, from among the members that constitute the seat 10, that interfere with the passage of electromagnetic waves. The biological sensors each have a first sensor 100 and a second sensor 200 that emit electromagnetic waves of different frequencies towards the person, and the first sensor 100 is disposed adjacent to the second sensor 200. Due to this configuration, it becomes easier to accurately detect biological information.