Needle device

A needle device comprising:

• an inner hub with a needle attached to a tip thereof, the inner hub having a through-hole penetrating the inner hub in a radial direction, the through-hole having a first end opening and a second end opening;
• a cylindrical body housing the inner hub;
• first and second recessed portions formed on an outer surface of the hub, the first and second recessed portions being connected by the first end opening of the through-hole;
• and
• third and fourth recessed portions formed on the outer surface of the hub, the third and fourth recessed portions being connected by the second end opening of the through-hole,
• wherein the first and fourth recessed portions are separated by at least a first separator surface, and the second and third recessed portions are separated by at least a second separator surface, and
• wherein the first recessed portion includes a portion whose depth becomes gradually shallower in a direction from the first end opening of the through-hole to the first separator surface, the second recessed portion includes a portion whose depth becomes gradually shallower in a direction from the first end opening of the through-hole to the second separator surface, the third recessed portion includes a portion whose depth becomes gradually shallower in a direction from the second end opening of the through-hole to the second separator surface, and the fourth recessed portion includes a portion whose depth becomes gradually shallower in a direction from the second end opening of the through-hole to the first separator surface.