An indwelling needle device includes a shield tube 4a, a flexible outer needle 8 fixed at a front end of the shield tube 4a, a hub 2 movable in a lumen of the shield tube 4a, with an infusion tube 3 being attached to an end thereof, and a rigid inner needle 1 fixed at a front end part of the hub and insertable into a lumen of the outer needle. The hub is provided with a lateral penetration path 2e that penetrates to a lumen of the hub. A space 14 between an outer surface of the hub and an inner surface of the shield tube communicates with a lumen 10 of the hub via the lateral penetration path. A sealing section 2c is provided on the outer surface of the hub, at a position on a rear end side with respect to the lateral penetration path, so as to keep liquid tightness for the space between the hub and the shield tube. Engagement recesses 2b are formed by the outer peripheral surface of the hub, at side wall portions on both sides of the lateral penetration path. A rear-end-side engagement projection 12b is provided on the inner surface of the shield tube so as to be engageable with the engagement recesses in a state in which the inner needle is housed in the lumen of the shield tube. A sufficient opening area for communication with the lumen of the hub is provided, while hub side walls where the opening is provided are coupled firmly with the front end part of the hub, and the hub can be made small in size.
