Hamster jumpy?

i just got my hamster about three days ago and he is so jumpy. today i put him in his ball and let him run around. then when i was puttin him back in his cage, i put my hand out so he could walk into it and he did. when i was setting him back down in his cage, he jumped right off and fell about 6 inches. hes fine though. but how do i get him to be less jumpy and to trust me more????? someone please help!!