To provide a filter in which the film-forming of a joint of a filter is prevented, and which is good-looking and is excellent in flexibility.

Heat welding tape 102 for a filter joins two or more filter cloths 101, and the heat welding tape 102 is a fabric woven by multiple weavings, and is characterized in that a first tissue which surface-contacts filter cloth 101 comprises a fabric woven by using a bulky textured yarn made of a thermoplastic resin for at least one of a warp or weft, the bulky textured yarn is made to be exposed to adhesion surface 103 which surface-contacts the filter cloth, and the adhesion surface is made a surface rich in a cushioning property.