Access by train is very straightforward and there are many trains departing from Sapporo and Chitose. Rapid trains also stop off in Noboribetsu.

For more information check JR Hokkaido: https://www.jrhokkaido.co.jp

Noboribetsu is easily accessible by buses as it is located on Route 36 which is the main road down to Hakodate. Regular buses from Sapporo and Chitose stop at Noboribetsu. 

For more information check out Donan bus: https://www.donanbus.co.jp

Driving from Sapporo to Noboribetsu takes about 1.5 hours by expressway at a cost of ¥3000, while taking the normal road along Route 36 takes about 3 hours.