The present invention relates to prioritizing special cells in 
cell selection in a 
cellular radio network. In a 
cellular radio network one or more cells provide a subscriber with special services or tariffs not offered to all subscribers. These cells are called subscriber's special cells. The 
mobile station measures an average reception level and calculates by means of them 
cell selection parameters on the basis of which the best 
cell is selected. In accordance with the invention, when the 
mobile station detects that the cell is one of cells of a special cell 
list stored in a memory, it checks first if the cell fulfils a minimum requirement of 
cell selection on the basis of the measured 
signal level. If the minimum requirement is fulfilled, the 
mobile station manipulates the calculation of the 
cell selection parameter of a special cell to the effect that the selection probability of a special cell is improved with respect to a 
normal cell. In a preferred embodiment of the invention, the manipulation of the calculation comprises a step of adding a predetermined margin to the measured 
signal level of a special cell before the 
cell selection parameter is calculated. This will minimize the possibility that the mobile 
station would accidentally be camped on a 
normal cell when it is within the area of a special cell.