The invention provides a method of producing a solid state lithium battery module in which the occurrence of short circuit caused by dendrites is suppressed. The invention solves this problem by providing a method of producing a solid state lithium battery module, including steps of: a pressing step of pressing a sulfide glass having an ion conductor containing a Li element, a P element, and a S element, and forming a solid electrolyte layer; and a restraining step of restraining a solid state lithium battery including the solid electrolyte layer, using restraining member, wherein, in the pressing step, the solid electrolyte layer is formed such that the average pore radius obtained by a mercury intrusion method is R (μm), and in the restraining step, the solid state lithium battery is restrained such that when the confining pressure is designated as P(MPa), the relationship: P≦−5900R+74 is satisfied.