PURPOSE: To keep an operation lever from returning to opened state even by removing hand from the lever and to prevent the falling off of fruit by providing a checking means to hold a lock lever in unlocked state or locked state.

CONSTITUTION: An opening tool 3 is operated with an operation tool 2 to clamp a fruit on a fruit tree and a lock lever 2g is kept to the locking side with a checking means 2j (e.g. spring) to lock the operation lever. The opening tool keeps the closed state to hold the fruit even by removing the hand from the operation lever.