what kind do you have and he should but it depends on him. try hand feeding him so he doesnt think of you as a threat. make up a free range if you have room. give him time a week is too soon imo to try and start holding him. my panthers loved to be held and wanted to free range all the time when they saw me. but try handfeeding first little treats like horn silk and butter worms.
How are you approaching him?
That has everything to do with it- pace you move, how your fingers are positioned and wether it is above them or lower.
They may also be stressed out due to placement of cage, how their cage is set up, temps and humidity, etc. it's best to open the cage and let them come to you, even if it takes an hour for them to venture out- paintence is key in your chameleon trusting you