I was always curious. The judge tells the husband he must pay $700.00 a
Month in child support. Can he demand the wife keep an itemized list
Of things she purchased on the child's behalf. He claims the wife is using his support money on herself?

No... he cannot "demand" the wife keep an itemized list of things she purchases for the children. Unless the children's well being isn't being met... there is nothing he can do. He needs to realized that the childsupport money includes necessities regarding help with payment on house/or rent of house, hygiene necessities, gas in vehicle to transport children, etc. etc.

Also... keep in mind that the mother does not determine the amount of childsupport. The court does.

Single4 is right HE cannot demand, but if he feels that the child's wellbeing is not being met, he can take her to court and the court can DEMAND.

It's not likely. No judge is going to want to be bothered with all that red tape. The law says he has to support his kid, period. He can claim all he wants (and there may indeed be some truth to his claims) but that has no legal bearing whatsoever. If you suspect that the child in question is being neglected, despite the $700.00 per month paid on his/her behalf, then that becomes a separate issue.

I was always curious. The judge tells the husband he must pay $700.00 a
month in child support. Can he demand the wife keep an itemized list
of things she purchased on the child's behalf. He claims the wife is using his support money on herself?
I just had this issue come up in my practice. I will say that it varies from court to court. My hometown court will say (and DOES say) the following: that 700.00 contributes to the "child's quality of life" in general. My court does not make custodial parents keep lists. Other courts in other states may require this. As a general rule, I always advise divorcing or conflicted parents to keep receipts of purchases for the children, especially major ones like dental work, etc. Never hurts to have the paperwork.

That said, some non-custodial parents will use the "list keeping" as a way to continue to control or harass the other parent. This is not good for the child/ren.