A radiator core support includes a radiator core support main body that is made of plastic material, a right fixing member and a left fixing member that are made of metal, and a first metal frame. The right fixing member and the left fixing member are fixed on a right side member and a left side member of a motor vehicle body, respectively. The first metal frame extends in a lateral direction of the motor vehicle body so as to connect the right fixing member and the left fixing member with each other and support the radiator core support main body.