To easily connect by laminating at least one layer made of a thermosoftening retardant substance on a layer containing a thermosoftening substance, and forming cracks oozy with the thermosoftening substance softened by a heat at the laminate.

At least a Y layer made of a thermosoftening retardant substance (B component) is laminated on a layer X containing a thermosoftening substance (component A). As the component A, a polyolfin resin or the like is used. As the component B for constituting the layer Y a substance having higher flow starting temperature than that of the component A for constituting the layer X is used. Then, cracks oozy with the component A softened by heat are formed at the layer Y. A depth of the crack is formed to arrive at a part where the component A for constituting the layer X exists in the degree that a strength of the laminate may not become insufficient. As a material to be connected, a material made of a component having high affinity to the component A at the surface of the side to be connected to the laminate is used, superposed on a surface of the cracks of the laminate and connected.