Abstract: A container feeder for feeding pillowlike uncompleted containers C1 each having a container body M1 and upper and lower ears U1, L1 projecting laterally from upper and lower ends of the container body to a conveyor 21 of a container forming device 14 for forming the uncompleted container C1 into a rectangular parallelepipedal completed container C2 comprises a slanting chute 101 having a lower end positioned at a starting end of a conveyor transport path, a first receiving member 134 so disposed as to be movable upward or downward along a chute transport path, the first receiving member 134 being movable into the chute transport path when moving downward to receive the lower end of the container body M1 of the container C1 falling along the chute 101 under gravity, and a second receiving member 144 so disposed as to be movable upward or downward along the chute transport path, the second receiving member 144 being movable into the chute transport path when moving downward to receive the upper ears U1 of the c