A container gripper comprising: grippers (4, 8) each of which includes a pair of holding pieces provided so as to be openable/closable by relative movement and includes holding portions allowing a head part (Bm) of a container to be taken in and out when the gripper (4, 8) is opened and restraining the head part (Bm) when the gripper is closed, wherein the holding of the container is alternately switched from a first gripper to a second gripper, so that the container is delivered, and wherein the holding portions of the first gripper include holding pieces (8a, 8b) that have a holding shape adapted to a neck part formed at the head part (Bm) and adapted to hold at least half of the circumference of the neck part, the holding portions of the second gripper include an upper holding piece and a lower holding piece, the upper holding piece includes a first and a second upper holding piece (5a, 5b) engageable with a groove of a male screw part formed at the head part (Bm) and being capable of holding at least half of the circumference of the groove, the lower holding piece includes a first and a second lower holding piece (6a, 6b) engageable with a lower portion of the neck part and being capable of holding at least half of the circumference of the lower portion, the holding portions are formed at one end of the upper holding pieces (5a, 5b) and of the lower holding pieces (6a, 6b), characterized in that, the first upper holding piece and the first lower holding piece can swing about a first shaft, the second upper holding piece and the second lower holding piece can swing about a second shaft, the shafts are disposed between an upper gripper body and a lower gripper body that are assembled by a support, and end portions of the shafts are fitted into the upper and lower gripper bodies (10, 18), an upper spring seat is formed at the other end of each of the first and second upper holding pieces (5a, 5b) and a lower spring seat is also formed at a portion of each of the first and second lower holding pieces (6a, 6b) corresponding to the respective upper spring seat with a first compression spring interposed between the first upper holding piece and the first lower holding piece and with a second compression spring interposed between the second upper holding piece and the second lower holding piece, such that each upper holding piece (5a, 5b) is biased by the respective compression spring so as to swing about the respective shaft, which comes into contact with an inner peripheral surface of a hole of each of the upper holding pieces (5a, 5b). grippers (4, 8) each of which includes a pair of holding pieces provided so as to be openable/closable by relative movement and includes holding portions allowing a head part (Bm) of a container to be taken in and out when the gripper (4, 8) is opened and restraining the head part (Bm) when the gripper is closed, wherein the holding of the container is alternately switched from a first gripper to a second gripper, so that the container is delivered, and wherein the holding portions of the first gripper include holding pieces (8a, 8b) that have a holding shape adapted to a neck part formed at the head part (Bm) and adapted to hold at least half of the circumference of the neck part, the holding portions of the second gripper include an upper holding piece and a lower holding piece, the upper holding piece includes a first and a second upper holding piece (5a, 5b) engageable with a groove of a male screw part formed at the head part (Bm) and being capable of holding at least half of the circumference of the groove, the lower holding piece includes a first and a second lower holding piece (6a, 6b) engageable with a lower portion of the neck part and being capable of holding at least half of the circumference of the lower portion, the holding portions are formed at one end of the upper holding pieces (5a, 5b) and of the lower holding pieces (6a, 6b), characterized in that, the first upper holding piece and the first lower holding piece can swing about a first shaft, the second upper holding piece and the second lower holding piece can swing about a second shaft, the shafts are disposed between an upper gripper body and a lower gripper body that are assembled by a support, and end portions of the shafts are fitted into the upper and lower gripper bodies (10, 18), an upper spring seat is formed at the other end of each of the first and second upper holding pieces (5a, 5b) and a lower spring seat is also formed at a portion of each of the first and second lower holding pieces (6a, 6b) corresponding to the respective upper spring seat with a first compression spring interposed between the first upper holding piece and the first lower holding piece and with a second compression spring interposed between the second upper holding piece and the second lower holding piece, such that each upper holding piece (5a, 5b) is biased by the respective compression spring so as to swing about the respective shaft, which comes into contact with an inner peripheral surface of a hole of each of the upper holding pieces (5a, 5b).