The invention provides a current detection circuit and a semiconductor memory apparatus using the current detection circuit thereof. The current detection circuit is capable of rapidly sensing the current flowing through a tiny bit line structure. A page buffer/sensing circuit of the invention includes: a transistor TP3 pre-charging a node SNS during a pre-charge period and providing a target constant current to the node SNS during a discharge period; a transistor TN3 pre-charging the bit line according to the voltage pre-charged to the node SNS; and a transistor TP2 connected to the node SNS. The transistor TP2 detects whether or not a current larger than the constant current supplied by the transistor TP3 is discharged from the bit line and outputs a detection result to a node SENSE.