An attachment assistance tool (100A, 100B, 100C, 100D) for an electronic component configured to be interposed between an electronic component attached to a terminal block and the terminal block, the attachment assistance tool (100A, 100B, 100C, 100D) comprising: a base portion configured to be arranged outside a housing of the terminal block such that a rear surface thereof abuts against a front wall of the housing and a part thereof faces a first through hole of the terminal block and a second through hole of the terminal block; a first insertion portion protruding from the rear surface of the base portion to be thereby inserted into the first through hole of the terminal block; and a second insertion portion protruding from the rear surface of the base portion to be thereby inserted into the second through hole of the terminal block, wherein a hollow first passage portion through which a first lead of the electronic component is to be inserted is provided to extend from the base portion to the first insertion portion, a hollow second passage portion through which a second lead of the electronic component is to be inserted is provided to extend from the base portion to the second insertion portion, and a receiving portion configured to receive and accommodate at least a rear portion of a component body of the electronic component is provided at a front-side position of the base portion, characterized in that: the receiving portion is located at least between the first passage portion and the second passage portion, the base portion has a pair of erected wall portions (111U, 111D) that face each other in a direction orthogonal to a direction connecting the first passage portion and the second passage portion, when viewed from a front side, and the receiving portion is defined by the pair of erected wall portions (111U, 111D). a base portion configured to be arranged outside a housing of the terminal block such that a rear surface thereof abuts against a front wall of the housing and a part thereof faces a first through hole of the terminal block and a second through hole of the terminal block; a first insertion portion protruding from the rear surface of the base portion to be thereby inserted into the first through hole of the terminal block; and a second insertion portion protruding from the rear surface of the base portion to be thereby inserted into the second through hole of the terminal block, wherein a hollow first passage portion through which a first lead of the electronic component is to be inserted is provided to extend from the base portion to the first insertion portion, a hollow second passage portion through which a second lead of the electronic component is to be inserted is provided to extend from the base portion to the second insertion portion, and a receiving portion configured to receive and accommodate at least a rear portion of a component body of the electronic component is provided at a front-side position of the base portion, characterized in that: the receiving portion is located at least between the first passage portion and the second passage portion, the base portion has a pair of erected wall portions (111U, 111D) that face each other in a direction orthogonal to a direction connecting the first passage portion and the second passage portion, when viewed from a front side, and the receiving portion is defined by the pair of erected wall portions (111U, 111D). the receiving portion is located at least between the first passage portion and the second passage portion, the base portion has a pair of erected wall portions (111U, 111D) that face each other in a direction orthogonal to a direction connecting the first passage portion and the second passage portion, when viewed from a front side, and the receiving portion is defined by the pair of erected wall portions (111U, 111D).