A disc brake for an automotive vehicle which includes: - a brake disc which extends in a plane transverse to an axially oriented axis of rotation of the disc; - a fixed support including at least two opposite arms having a generally vertical orientation each including a C-shaped cross-section axial housing horizontally opening towards the opposite arm and which is delimited by an upper face and a lower face with a generally horizontal orientation; - for each arm of the fixed support, a rail which closely fits to the walls of the housing, which is attached to the fixed support and which includes at least one C-shaped cross-section sliding axial upper part which is received and locked in the associated housing, this upper part including an horizontal lower wing, an horizontal upper wing, and a bottom vertical wing which connects both lower and upper wings together - at least one brake pad including two mounting opposite lateral lugs each of which is received in an associated housing of an associated arm with a said rail interposed therebetween; wherein said at least one brake pad includes a vertical transverse plate which carries a friction lining a friction transverse face of which cooperates with an associated braking track of the disc, the brake pad being axially slidably mounted in the fixed support between an active front position in which said friction face bears against the associated braking track of the disc, and an inactive rear position in which said friction face is axially spaced apart from said associated braking track of the disc, by a determined operating play; - and at least one spring for elastically returning the brake pad to its inactive position including at least one portion for attaching the elastic return spring to the fixed support, and including a rigid connection branch, with an axial orientation parallel to the sliding direction of the brake pad, and which is connected to the brake pad, characterised in that: - the portion for attaching the elastic return spring to the fixed support includes an attachment tab which forwardly extends along an axial direction parallel to the sliding direction of the brake pad; - at least one wing of the rail associated with this spring includes an attachment tongue which extends axially rearwardly; - the attachment tab and the attachment tongue include complementary cooperation connection means having complementary shapes. - a brake disc which extends in a plane transverse to an axially oriented axis of rotation of the disc; - a fixed support including at least two opposite arms having a generally vertical orientation each including a C-shaped cross-section axial housing horizontally opening towards the opposite arm and which is delimited by an upper face and a lower face with a generally horizontal orientation; - for each arm of the fixed support, a rail which closely fits to the walls of the housing, which is attached to the fixed support and which includes at least one C-shaped cross-section sliding axial upper part which is received and locked in the associated housing, this upper part including an horizontal lower wing, an horizontal upper wing, and a bottom vertical wing which connects both lower and upper wings together - at least one brake pad including two mounting opposite lateral lugs each of which is received in an associated housing of an associated arm with a said rail interposed therebetween; wherein said at least one brake pad includes a vertical transverse plate which carries a friction lining a friction transverse face of which cooperates with an associated braking track of the disc, the brake pad being axially slidably mounted in the fixed support between an active front position in which said friction face bears against the associated braking track of the disc, and an inactive rear position in which said friction face is axially spaced apart from said associated braking track of the disc, by a determined operating play; - and at least one spring for elastically returning the brake pad to its inactive position including at least one portion for attaching the elastic return spring to the fixed support, and including a rigid connection branch, with an axial orientation parallel to the sliding direction of the brake pad, and which is connected to the brake pad, - the portion for attaching the elastic return spring to the fixed support includes an attachment tab which forwardly extends along an axial direction parallel to the sliding direction of the brake pad; - at least one wing of the rail associated with this spring includes an attachment tongue which extends axially rearwardly; - the attachment tab and the attachment tongue include complementary cooperation connection means having complementary shapes.