A cleaning sheet including a cleaning layer which has a microasperity shape having an arithmetic average roughness Ra of 0.05 μm or less and a maximum height Rz of 1.0 μm or less. Preferably, a substantial surface area of the cleaning layer per a flat surface of 1 mm2 is 150% or more of a substantial surface area of a silicon wafer mirror surface per a flat area of 1 mm2. The cleaning sheet may be provided on at least one surface of a transfer member so that the transfer member has a cleaning function. When the cleaning sheet or the transfer member having a cleaning function is transferred in a substrate processing apparatus in place of a substrate to be processed therein, the cleaning sheet contacts and cleans a site of the substrate processing apparatus.