Getting around Milan is easy once you know where to start. So get an ATM Special Ticket (Biglietti Speciali ATM) and take the easy option.
These tickets will help you move easily, day or night, around Milan’s Public Transport network (buses, trams and underground/metro). Also don’t forget that you can use your tickets for travel to and from Milan’s Linate airport.
Ticket prices start from € 1.00 for a ticket valid for 75 minutes after stamping for a single journey on the underground or rail network or you can buy a Carnet of 10 standard tickets for € 9.20. If you are staying longer than one day travel cards for 4 days cost € 8,00 or € 6,50 the 2 day version.
For more info check out the ATM website