A damping member for a rolling guide device, the rolling guide device including: a track rail (40, 41); and a moving block (43, 44), which is assembled to the track rail through intermediation of a plurality of rolling elements, and is configured to move along the track rail, the damping member comprising: a friction member which includes a sliding contact pad configured to be in contact with at least the track rail; and a fixing holder, which is configured to press the friction member against the track rail (40, 41) and couple the friction member to the moving block, the damping member being provided to the track rail (40, 41)in series with the moving block (43, 44), wherein the fixing holder includes: a holding portion which includes a pressing plate configured to press the sliding contact pad against the track rail (40, 41) and cover the track rail (40, 41) from above the friction member; and a pair of coupling arms which extends from the holding portion along a longitudinal direction of the track rail (40, 41) to hold the moving block (43, 44), the damping member being characterised in that the friction member includes a thick portion configured to be positioned between the holding portion of the fixing holder and the moving block, and wherein, in movement of the moving block (43, 44) along the track rail (40, 41), any one of the moving block (43, 44) and the fixing holder presses the thick portion of the friction member in the longitudinal direction of the track rail. a track rail (40, 41); and a moving block (43, 44), which is assembled to the track rail through intermediation of a plurality of rolling elements, and is configured to move along the track rail, a friction member which includes a sliding contact pad configured to be in contact with at least the track rail; and a fixing holder, which is configured to press the friction member against the track rail (40, 41) and couple the friction member to the moving block, the damping member being provided to the track rail (40, 41)in series with the moving block (43, 44), wherein the fixing holder includes: a holding portion which includes a pressing plate configured to press the sliding contact pad against the track rail (40, 41) and cover the track rail (40, 41) from above the friction member; and a pair of coupling arms which extends from the holding portion along a longitudinal direction of the track rail (40, 41) to hold the moving block (43, 44), the damping member being characterised in that a holding portion which includes a pressing plate configured to press the sliding contact pad against the track rail (40, 41) and cover the track rail (40, 41) from above the friction member; and a pair of coupling arms which extends from the holding portion along a longitudinal direction of the track rail (40, 41) to hold the moving block (43, 44), the damping member being characterised in that the friction member includes a thick portion configured to be positioned between the holding portion of the fixing holder and the moving block, and wherein, in movement of the moving block (43, 44) along the track rail (40, 41), any one of the moving block (43, 44) and the fixing holder presses the thick portion of the friction member in the longitudinal direction of the track rail.