A transfer roller may be omitted, and stability in a traveling state of a belt member 121 in a reciprocating roller 63 and a supply roller 64 can be provided. A manufacturing method of a composite sheet that continuously supplies, to a sheet surface of a belt-like sheet 103b that is transported continuously in a predetermined transporting direction, an elastic belt member 121 while reciprocating the belt member in an intersecting direction that intersects the transporting direction, and thus bonds the belt member 121 to the sheet surface of the belt-like sheet 103b while continuously changing a bonding position of the belt member 121 on the sheet surface in the intersecting direction, the method includes: causing the belt member 121 to surface contact with the sheet surface of the belt-like sheet 103b and to bond thereto, by supplying the belt-like sheet 103b to an outer circumferential surface of a bonding roll 50 that rotates in a direction along the transporting direction, and supplying the belt member 121 via a guide member 60 to a part of the belt-like sheet 103b that is brought in contact with the outer circumferential surface of the bonding roll 50 and overlapping the belt member 121 to the part, the guide member 60 having a reciprocating roller 63 that reciprocates in the intersecting direction and a supply roller 64 that is provided at a predetermined position and to which the belt member 121 is supplied to wrapping the belt member 121 subsequently around the outer circumferential surface of the supply roller 64 and the outer circumferential surface of the reciprocating roller 63 and leading the belt member to the belt-like sheet 103b oscillating the supply roller 64 so that the outer circumferential surface of the supply roller 64 faces toward the reciprocating roller 63 in accordance with a reciprocating motion of the reciprocating roller 63.
