To reliably avoid an interference between a footrest and an obstruction in a footrest device for a vehicular seat.

A leg rest 13 and a seat back 12 are mounted for turning movement on the front and rear of a seat cushion 11 of a vehicular seat 8, and the footrest 19 is mounted for reciprocating movement on the leg rest 13. A seat back actuator 15, a leg rest actuator 17 and a footrest actuator 19 provide angle adjustment of the seat back 12 and the leg rest 13 and positioning of the footrest 14. A proximity sensor 21 is disposed at a tip portion of the footrest 21. When the proximity sensor 21 detects approach of an obstruction, downward turning movement of the leg rest 13 is stopped, and the footrest 14 is moved back. When the leg rest 13 or the footrest 14 is moved, the footrest can be reliably prevented from interfering with the obstruction such as baggage of a passenger or the like.