The paper presents an estimation of changes of apples firmness during storage in various conditions. Apples were stored in a cold-room and in a cellar. The apple firmness tests were carried out on an MTS strength tester connected to a computer. The tests consisted in the measurement of the values of strength and deformation in the range of destructive deformation. Additionally the hardness of skin was tested in puncture tests. Analysis of the results was conducted by means of multifactorial analysis test with multiple repetitions for all compression tests and measurements of firmness. The independent variables were the place of storage, the shape of sample and the period of storage. The Duncan test showed homogenous groups. The changes of firmness and period of storage were described and the theoretical curves with the best fit to the actual results. The maximum values of force in the compression tests and in the apple skin puncture tests were determined. In the case of apples stored in the cold-room December was the decisive month when a slow down of the firmness changes was observed. The largest changes of apple skin strength were noted for the samples stored in the cellar.