A vehicle seat (1; 800; 900) comprising a seat cushion part and a seat back part, wherein the seat cushion part has a cushion frame unit (10; 810; 910) supporting a cushion member for the seat cushion part and the seat back part has a back frame unit (30; 830; 930) supporting a cushion member for the seat back part, a left and right side frames constituting the cushion frame unit are coupled to and supported by a left and right sliders, respectively, constituting a seat slide device (40; 840; 940), and are each constituted of one or a plurality of plate-shaped frames (111, 112) long in a forward and backward direction and formed of a thin material made of metal with a predetermined thickness, a plurality of beams (121 - 125) are bridged across the left and right side frames of the cushion frame unit, at least one of the left and right side frames is supported on the seat slide device (40; 840; 940) via a truss support part receiving a force in the forward and backward direction, the truss support part being formed of a coupling support part with respect to the slider, the beams bridged across the left and right side frames, and an inter-node connecting part coupling the coupling support part and the beams in a direction substantially orthogonal to a disposition direction of the beams, characterized by coupling support parts for the left and right side frames and the left and right sliders provided between a center part and a rear edge in the forward and backward direction of the side frames, wherein the left and right coupling support parts are coupled by a shaft member and the truss support part is formed of the shaft member, two beams (123, 125) out of the plural beams disposed between the center part and the rear edge in the forward and backward direction of the side frames, and inter-node connecting parts respectively connecting vicinities of respective ends of the two beams, and vicinities of ends of the shaft member and the vicinities of respective ends of the two beams. the seat cushion part has a cushion frame unit (10; 810; 910) supporting a cushion member for the seat cushion part and the seat back part has a back frame unit (30; 830; 930) supporting a cushion member for the seat back part, a left and right side frames constituting the cushion frame unit are coupled to and supported by a left and right sliders, respectively, constituting a seat slide device (40; 840; 940), and are each constituted of one or a plurality of plate-shaped frames (111, 112) long in a forward and backward direction and formed of a thin material made of metal with a predetermined thickness, a plurality of beams (121 - 125) are bridged across the left and right side frames of the cushion frame unit, at least one of the left and right side frames is supported on the seat slide device (40; 840; 940) via a truss support part receiving a force in the forward and backward direction, the truss support part being formed of a coupling support part with respect to the slider, the beams bridged across the left and right side frames, and an inter-node connecting part coupling the coupling support part and the beams in a direction substantially orthogonal to a disposition direction of the beams, characterized by coupling support parts for the left and right side frames and the left and right sliders provided between a center part and a rear edge in the forward and backward direction of the side frames, wherein the left and right coupling support parts are coupled by a shaft member and the truss support part is formed of the shaft member, two beams (123, 125) out of the plural beams disposed between the center part and the rear edge in the forward and backward direction of the side frames, and inter-node connecting parts respectively connecting vicinities of respective ends of the two beams, and vicinities of ends of the shaft member and the vicinities of respective ends of the two beams.