Method of producing electrochemical device, and the electrochemical device

A method of producing an electrochemical device which comprises a laminate having a first electrode and a second electrode facing each other, and a porous separator adjacently placed between the first electrode and the second electrode, and in which the first electrode and the second electrode are electrodes each having a collector, and a porous material layer with electron conductivity placed between the collector and the separator,

• the method comprising making the porous material layer, using as constituent materials, at least particles of a porous material with electron conductivity, and a thermoplastic resin being capable of binding the particles of the porous material together and having a softening point TB lower than a softening point TS of the separator,
• the method comprising a thermal treatment step of thermally treating the laminate at a thermal treatment temperature T1 satisfying a condition represented by Formula (1) below, thereby bringing the collector of the first electrode, the porous material layer of the first electrode, the separator, the porous material layer of the second electrode, and the collector of the second electrode in the laminate into an integrated state.
• TB≦T1<TS (1).