Can. 932

§1. The eucharistic celebration is to be carried out in a sacred place unless in a particular case necessity requires otherwise; in such a case the celebration must be done in a decent place.

§2. The eucharistic sacrifice must be carried out on a dedicated or blessed altar; outside a sacred place a suitable table can be used, always with a cloth and a corporal.

Read the whole title TITLE IIIThe Most Holy Eucharist 897–958