It comprises reception means for enabling coins to access the coin mechanism; identification means for determining the acceptability, type and value of the accessing coins; a coin storage compartment for selectively housing and delivering the coins destined for being refunded to a user, where the coin storage compartment comprises a plurality of tubes, according to rows and columns; extraction means for selectively extracting the coins from the tubes; and raising means for selectively raising any of the tubes during extraction of the coins, in order to momentarily provide a space for each coin to exit without colliding with the adjacent tubes. It allows greater optimisation of the use of the space destined for the coin mechanism, particularly the coin storage compartment.