Needle assembly

A needle assembly comprising:

• a needle projecting from a needle hub;
• a needle tip cover having a needle hole into which the needle is inserted and whose inside diameter dimension is larger than an outside diameter dimension of the needle, the needle tip cover being externally provided about the needle so as to be movable in a needle axis direction and configured to cover a needle tip by being moved to a distal end side beyond the needle tip;
• a fixed-side guide fixedly provided to the needle;
• and
• a moving-side guide integrally provided to the needle tip cover, wherein
• the moving-side guide is engaged with the fixed-side guide so as to provide a guide mechanism to guide the needle tip cover from a proximal end side of the needle toward the distal end side thereof while keeping the needle tip cover noncontact with the needle until the needle tip cover reaches a position beyond the needle tip and, at the position beyond the needle tip, to deviate the needle tip cover in a direction in which the needle hole goes away from a center axis of the needle so as to avoid contact of the needle tip with the needle hole while guiding the needle tip cover to a position where the needle tip cover covers the needle tip.