A sacristy is a room for keeping vestments (such as the cassock and chasuble) and other church furnishings, sacred vessels and church treasures. The sacristy is usually located inside the church (for example, near one of the side altars or more usually behind or to the side of the main altar) but it could be an annex or separate building (as in some monasteries).
A person in charge of sacristy is called sacristan.
The sacristy is also where the priest and attendants dress and prepare before the service. They will return there at the end of the service to remove the special robes and put away any of the vessels used in the service.
The word "sacristy" derives from the Latin "sacrastia".
He was the assistant of the sacristan, was subject to the archdeacon, and discharged duties very similar to those of the sacristan.
The Sodality of St. John Berchmans, known as the Pious Association of Servers of Mass and Sacristans, was founded by Vincent Basile, S.J., missionary Apostolic among the southern Slavs, for lay acolytes, choir boys, sacristans, and all who have any duty to perform in the services of the Church.
Its object is to induce all its members to perform their duties piously and in a manner befitting the ceremonies in which they participate, for the glory of God and the edification of the faithful.
He should have no difficulty, if the sacristan is a man of order, and with the power of organization, in finding his cassock and surplice on their proper peg and his sanctuary shoes in their box, if the muddy lanes of the parish make such footwear necessary.
The priest or sacristan responsible for the training will be wise to begin at the beginning, which is to see that his own part in the making ready for a service to be performed reverently and without haste is punctiliously carried out.
Therefore a sacristan needs the education of residence in a three-ton yacht to qualify him or her for the charge of the circumscribed chamber provided for the accommodation of the articles required.