After the guest checked into the hotel, he found that there was something wrong with the mineral water he drank. Which department managed it?

It is managed by the Market Supervision Administration.

The regulatory responsibilities of the Market Management Supervision Administration cover the original industrial and commercial administration, quality and technical supervision, intellectual property, prices, catering supervision, alcohol product supervision and other departmental responsibilities.

A hotel is a place where guests can stay and eat. The hotel mainly provides tourists with accommodation services, life services and facilities (before bed service), catering, games, entertainment, shopping, business center, banquets and conference facilities.