Depending on your ticket class you are allowed 1-2 pieces of carry on luggage as shown below:
Economy Light: 1 small bag not to exceed 8kg in total and no larger than 40cm x 30cm x 10cm.
Economy Classic: 1 small bag as described above plus 1 carry on bag not to exceed 55cm x 40cm x 20cm. Both bags cannot weigh more than 8kg combined.
Premium Economy: 1 small bag and 1 carry on bag conforming to the dimensions above, combined weight no greater than 10kg
Business Class: A small bag and 2 carry on bags, a single bag must not weigh more than 10kg and the total weight of all bags must not be greater than 10kg.