The temperature distributions in a vial during freeze-drying of a skim milk solution were experimentally determined by, superposing temperature histories measured at different positions in separate experimental runs. The obtained temperature distribution clearly indicates the multi-dimensional drying characteristics of freeze-drying in a vial. Along with the experiments, a numerical analysis program based on a finite volume method with a moving grid system was developed and its validity, was tested. (C) 2004 Elsevier Ltd. All rights reserved.