To obtain a separator plate of a wet-type multiple-disc clutch whose friction property is improved by decreasing an initial friction coefficient at the time of its engagement.

A continuous irregularity with minute recess-projection portions is formed along a circle Y formed at roots of spline teeth 72 formed in an outer circumferential surface 73 of the separator plate 7. A numeral symbol 76 denotes the recess potion. A distance between the teeth is made larger than a width D of one tooth T. An oil film is formed at the early time of the engagement in the recess portions formed by the irregularity to decrease the initial friction coefficient, thus improving the friction property. When the separator 7 is manufactured, a circumferential surface 74 without the spline teeth is punched out and then the spline teeth of the outer circumferential surface 73 are punched out.