Yes, this trap is effective.  It also is sturdy and lasts a long time.  You have to check it every morning and set it every night unless you don;t care if the mice die in the trap.  It holds more than one mouse easily and is well ventilated.  It opens and closes easily, unlike the clear shaded plastic versions of similar design.  I find the best bait is a bit of chocolate bar and a few drops of water in a plastic bottle cap.