To give milk to a baby when necessary by parting a chamber containing solid milk agent and a chamber containing liquid by a parting part, peeling part of the parting part for communicating the two chambers with each other, and providing a mouth part comprising a nipple of which inner wall is installed on an outer wall at a neck part.

A second chamber 2 for containing liquid 4, and a first chamber 1 for containing solid milk agent 3 are formed. A parting belt part 9 to part the first and the second chambers is pressurized from an outer part to be weakly sealed at such a temperature that flexible resin sheets are not fused with each other. As pressure is applied from the outer side of the second chamber, inner seal is peeled, the second chamber is communicated with the first chamber, and the solid milk agent 3 is mixed with the liquid 4. After a cover sheet 8 is removed from a container mouth part 7, a cover sheet 16 of an inner cap 12 is removed, and a female thread 15 in the inner cap 12 which is covered with an outer cap 13 is threaded with a male thread 6 in a container neck part 5. By removing the outer cap 13, milk can be given to a baby when necessary.