A method for fixing a metal joint adapted to be fitted into a hole formed in one end surface of a building component having an elongated shape, the metal joint comprising: a small diameter portion having an elongated shape and an outer diameter smaller than an inner diameter of the hole; and two large diameter portions fixed to the small diameter portion individually at two locations spaced apart from each other in a longitudinal direction of the small diameter portion, each large diameter portion having an outer diameter corresponding to the inner diameter of the hole, each of the large diameter portions comprising a spring ring, each spring ring having an outer diameter larger than the inner diameter of the hole, each spring ring being capable of retaining a position with respect to the hole by elastic force, wherein irregularities are formed on an outer peripheral surface of the small diameter portion in a section between the two large diameter portions; and wherein the method comprises the steps of: forming the hole for fitting the metal joint in the one end surface of the building component, and also forming an adhesive injection hole and an adhesive fill check hole, both of which communicate with the hole for fitting the metal joint, in one side surface of the building component; fitting the metal joint into the hole formed in the building component until reaching a predetermined position; injecting an adhesive into the adhesive injection hole to supply the adhesive to a gap between the small diameter portion of the metal joint and the building component; and checking whether the adhesive has flowed out of the adhesive fill check hole, and when the adhesive has flowed out, stopping injecting the adhesive and curing the adhesive until the adhesive is sufficiently hardened. a small diameter portion having an elongated shape and an outer diameter smaller than an inner diameter of the hole; and two large diameter portions fixed to the small diameter portion individually at two locations spaced apart from each other in a longitudinal direction of the small diameter portion, each large diameter portion having an outer diameter corresponding to the inner diameter of the hole, each of the large diameter portions comprising a spring ring, each spring ring having an outer diameter larger than the inner diameter of the hole, each spring ring being capable of retaining a position with respect to the hole by elastic force, wherein irregularities are formed on an outer peripheral surface of the small diameter portion in a section between the two large diameter portions; and wherein the method comprises the steps of: forming the hole for fitting the metal joint in the one end surface of the building component, and also forming an adhesive injection hole and an adhesive fill check hole, both of which communicate with the hole for fitting the metal joint, in one side surface of the building component; fitting the metal joint into the hole formed in the building component until reaching a predetermined position; injecting an adhesive into the adhesive injection hole to supply the adhesive to a gap between the small diameter portion of the metal joint and the building component; and checking whether the adhesive has flowed out of the adhesive fill check hole, and when the adhesive has flowed out, stopping injecting the adhesive and curing the adhesive until the adhesive is sufficiently hardened. forming the hole for fitting the metal joint in the one end surface of the building component, and also forming an adhesive injection hole and an adhesive fill check hole, both of which communicate with the hole for fitting the metal joint, in one side surface of the building component; fitting the metal joint into the hole formed in the building component until reaching a predetermined position; injecting an adhesive into the adhesive injection hole to supply the adhesive to a gap between the small diameter portion of the metal joint and the building component; and checking whether the adhesive has flowed out of the adhesive fill check hole, and when the adhesive has flowed out, stopping injecting the adhesive and curing the adhesive until the adhesive is sufficiently hardened.