A substrate mounting structure comprising: a substrate member including a substrate portion (Bd), the substrate portion (Bd) having a first surface (Sa) and a second surface (Sb) opposite to each other in a thickness direction of the substrate portion (Bd), first to fourth edges (eg1, eg2, eg3, eg4), and a predetermined thickness in the thickness direction; a first mounting member on which the substrate member is placed; and a second mounting member attached to the first mounting member to hold the substrate member on the first mounting member, wherein: the first mounting member includes a first restricting portion abutting on the first edge to restrict movement of the substrate member, a second restricting portion (Se2, Se3) abutting on the second edge to restrict movement of the substrate member, and a third restricting portion (Sk1, Sk2) abutting on the second surface (Sb) to restrict movement of the substrate member in the thickness direction; and the second mounting member includes a fourth restricting portion abutting on the third edge to restrict movement of the substrate member, a fifth restricting portion abutting on the fourth edge to restrict movement of the substrate member, and a sixth restricting portion abutting on the first surface (Sa) to restrict movement of the substrate member. a substrate member including a substrate portion (Bd), the substrate portion (Bd) having a first surface (Sa) and a second surface (Sb) opposite to each other in a thickness direction of the substrate portion (Bd), first to fourth edges (eg1, eg2, eg3, eg4), and a predetermined thickness in the thickness direction; a first mounting member on which the substrate member is placed; and a second mounting member attached to the first mounting member to hold the substrate member on the first mounting member, wherein: the first mounting member includes a first restricting portion abutting on the first edge to restrict movement of the substrate member, a second restricting portion (Se2, Se3) abutting on the second edge to restrict movement of the substrate member, and a third restricting portion (Sk1, Sk2) abutting on the second surface (Sb) to restrict movement of the substrate member in the thickness direction; and the second mounting member includes a fourth restricting portion abutting on the third edge to restrict movement of the substrate member, a fifth restricting portion abutting on the fourth edge to restrict movement of the substrate member, and a sixth restricting portion abutting on the first surface (Sa) to restrict movement of the substrate member. the first mounting member includes a first restricting portion abutting on the first edge to restrict movement of the substrate member, a second restricting portion (Se2, Se3) abutting on the second edge to restrict movement of the substrate member, and a third restricting portion (Sk1, Sk2) abutting on the second surface (Sb) to restrict movement of the substrate member in the thickness direction; and the second mounting member includes a fourth restricting portion abutting on the third edge to restrict movement of the substrate member, a fifth restricting portion abutting on the fourth edge to restrict movement of the substrate member, and a sixth restricting portion abutting on the first surface (Sa) to restrict movement of the substrate member.