A composite material structure comprising: a first structure member made of metal and extending in a longitudinal direction of the composite material structure and having holes formed therein; a second structure member (3a,3c) formed as a composite material made of fiber reinforced plastics extending in the longitudinal direction and connected to a side portion of the first structure member, wherein the first structure member and the second structure member (3a,3c) are joined to one another on a division surface extending in the longitudinal direction of the composite material structure; and a plurality of stringers that are provided in the longitudinal direction of the composite material structure, wherein one of the stringers and the first structure member are fixed by a fastener and/or by bonding and wherein the stringer and the second structure member (3a,3c) are fixed by a fastener and/or by bonding, wherein the first structure member includes: a fixed thickness region (3b-1) adjacent to the second structure member (3a,3c), wherein the fixed thickness region (3b-1) is formed in thickness in a direction perpendicular to the longitudinal direction substantially the same as the thickness of the second structure member (3a,3c); and a peripheral edge region (3b-2) further increased in thickness compared to the fixed thickness region (3b-1) and reinforcing peripheral edge portions of the holes, wherein the peripheral edge region (3b-2) is surrounded by the fixed thickness region (3b-1). a first structure member made of metal and extending in a longitudinal direction of the composite material structure and having holes formed therein; a second structure member (3a,3c) formed as a composite material made of fiber reinforced plastics extending in the longitudinal direction and connected to a side portion of the first structure member, wherein the first structure member and the second structure member (3a,3c) are joined to one another on a division surface extending in the longitudinal direction of the composite material structure; and a plurality of stringers that are provided in the longitudinal direction of the composite material structure, wherein one of the stringers and the first structure member are fixed by a fastener and/or by bonding and wherein the stringer and the second structure member (3a,3c) are fixed by a fastener and/or by bonding, wherein the first structure member includes: a fixed thickness region (3b-1) adjacent to the second structure member (3a,3c), wherein the fixed thickness region (3b-1) is formed in thickness in a direction perpendicular to the longitudinal direction substantially the same as the thickness of the second structure member (3a,3c); and a peripheral edge region (3b-2) further increased in thickness compared to the fixed thickness region (3b-1) and reinforcing peripheral edge portions of the holes, wherein the peripheral edge region (3b-2) is surrounded by the fixed thickness region (3b-1). a fixed thickness region (3b-1) adjacent to the second structure member (3a,3c), wherein the fixed thickness region (3b-1) is formed in thickness in a direction perpendicular to the longitudinal direction substantially the same as the thickness of the second structure member (3a,3c); and a peripheral edge region (3b-2) further increased in thickness compared to the fixed thickness region (3b-1) and reinforcing peripheral edge portions of the holes, wherein the peripheral edge region (3b-2) is surrounded by the fixed thickness region (3b-1).