A holder includes a bracket, a first side portion, two second side portions and a third side portion. The bracket includes a support arm and an elastic plate inclinedly connected to the support arm. The first side portion is connected to one end of the support arm, and located at one side of the bracket. The second side portions are respectively connected to two opposite sides of the support arm, and collectively located at the side of the bracket. The third side portion is connected to one end of the elastic plate opposite to the support arm, and located at the same side of the bracket with the second side portions. When the elastic plate is pressed to be flush with the support arm, the bracket, the first side portion, the second side portions and the third side portion collectively form a holding space for holding a loaded object.