Is there an ATM machine at arrivals Capital Airport T3 for getting local money?

Yes. Besides the ATM, there are also several foreign exchange counters in T3 for your convenience.
Hereunder is the detailed information:
1. ICE:
T3-C Departure Hall on the fourth floor
East exit of International Luggage Claim Hall
2. Hang Seng Bank
International Arrival Hall’s Public Area
Opposite to Boarding Gate No.E20 of T3-E International Departure Lobby on the second floor

Many detailed English signs will help you find the direction easily. :)