An impression material automatic kneading apparatus where packages can be replaced easily is provided. Included are: a holder that holds a package containing pasty materials and a main body that is connected to an opening part of the package, sucks the pasty materials, and kneads the pasty materials. The holder includes: a holding member that holds the opening part of the package a moving member that holds an end part that is in a side opposite to the opening part of the package, the moving member movably arranged along the holding member and an elastic member one end of which is attached to the holding member and another end of which is attached to the moving member. The holder can be attached to and detached from the main body in a state where the package is energized by the elastic member.
