A snap-ring supplying device includes a magazine (10) containing C-shaped snap rings (S) piled together each of which has a gap, an extrusion member (25) that pushes out a snap ring occupying the lowest position in the magazine so that the gap (S1) of the snap ring is directed forwardly in an extruding direction, a conveying path (23) that conveys the snap ring pushed out by the extrusion member to an area in which the snap ring is contracted to reduce the diameter of the snap ring, a projection-strip guide wall (26) formed to stand upwardly in a substantially vertical direction with a width that is defined by forming a pair of concave parts (28) and that can enter the gap of the snap ring in a termination area of the conveying path, and an oscillating member (31) and urging members (32, 33) serving as a restricting mechanism (30) that restricts the gap of the snap ring so that the gap is directed in a direction from the magazine to the projection-strip guide wall. With this structure, the direction of the gap is restricted during conveyance, and hence the snap ring can be supplied to the ring-contracting area while reliably changing the attitude of the snap ring.