A holder (10; 110; 210; 310) for a series of open-end wrenches or ring wrenches, each wrench comprising at least a working head (14; 16, 314, 316) and a handle (18; 318), the holder being of the type comprising a base (20; 120; 220; 320) with a substantially planar general shape; a plurality of housings (22; 122; 222; 322) parallel to one another, each housing being designed to receive and retain the handle (18; 318) of a corresponding wrench from the series in a predetermined position in the holder (10; 110; 210; 310); a plurality of receiving and retaining means (32; 332) for the wrench head (14; 16, 314, 316), each receiving and retaining means (32; 332) being associated with a housing (22; 122; 222; 322) and being designed to receive and retain the working head (14; 16, 314, 316) of the corresponding wrench in a predetermined position in the holder (10; 110; 210; 310); the plurality of housings (22; 122; 222; 322) and the plurality of receiving and retaining means (32; 332) being secured to the base (20; 120; 220; 320), each housing (22; 122; 222; 322) comprising two partitions (24, 26, 28; 124, 126, 128; 224, 226, 228; 324) substantially parallel to one another, positioned substantially perpendicular to the base and defining a channel (22; 122; 222; 322), at least one of the partitions (24, 26, 28; 124, 126, 128; 224, 226, 228; 324) including a positioning means (30; 130; 230; 330) of the handle (18; 318), - each channel (22; 122; 222; 322) has a width slightly larger than the smallest dimension of the handle (18; 318) of the associated wrench (12; 312); characterized in that - the receiving and retaining means (32; 332) of the wrench head (14; 16, 314, 316) comprise either a stepped bar, extending substantially perpendicular to the longitudinal direction of the channels (22; 122; 222; 322), the bar having segments with dimensions complementary to those of an inner female cavity of the wrench heads of the series, or a series of stepped receptacles, each receptacle extending in the extension of the associated channel, the series of receptacles having segments with shapes complementary to the outer shapes of the wrench heads (16, 314, 316) of the series; and - the receiving and retaining means (32; 332) of the wrench head (14; 16, 314, 316) define, at one end (38; 338) of the base (20; 120; 220; 320), a receiving area (39; 339) of the wrench head (14; 16, 314, 316), said end of the base (20; 120; 220; 320) forming a longitudinal retaining stop of the wrench head (14; 16, 314, 316), such that the wrench head is transversely retained by the receiving and retaining means and longitudinally retained by said stop. - each channel (22; 122; 222; 322) has a width slightly larger than the smallest dimension of the handle (18; 318) of the associated wrench (12; 312); - the receiving and retaining means (32; 332) of the wrench head (14; 16, 314, 316) comprise either a stepped bar, extending substantially perpendicular to the longitudinal direction of the channels (22; 122; 222; 322), the bar having segments with dimensions complementary to those of an inner female cavity of the wrench heads of the series, or a series of stepped receptacles, each receptacle extending in the extension of the associated channel, the series of receptacles having segments with shapes complementary to the outer shapes of the wrench heads (16, 314, 316) of the series; and - the receiving and retaining means (32; 332) of the wrench head (14; 16, 314, 316) define, at one end (38; 338) of the base (20; 120; 220; 320), a receiving area (39; 339) of the wrench head (14; 16, 314, 316), said end of the base (20; 120; 220; 320) forming a longitudinal retaining stop of the wrench head (14; 16, 314, 316), such that the wrench head is transversely retained by the receiving and retaining means and longitudinally retained by said stop.