PURPOSE: To prevent leakage of hot water and coffee powder in instant coffee extraction pack of regular coffee by a method wherein a bag type filter is made of a filter and is sealed up with coffee powder filled therein, and a hanging part is attached to symmetrical positions on the front and the rear of the sealed-up mouth of the bag type filter.

CONSTITUTION: A bag type filter 2 is formed in the shape of upside-down triangle in the size of a cupful, and is filled with coffee powder 3. The mouth 4 of the bag type filter 2 is closed flat and is temporarily sealed up with a temporary sealing part 6. Both ends of a hanging part 8 are attached to the termporary sealing part 6 on symmetrical positions on the front and the rear of the mouth 4. Therefore, the bag type filter 2 can be mounted to the extent of cupful capacity, and as the mouth 4 can be opened wide, hot water can be poured easily. As the filter 2 can be taken out stably, leakage of hot water or coffee powder can be prevented.