A breathing assistance apparatus includes a main body unit, a head strap unit, a nasal prong unit, and an intake unit. The main body unit has a rearwall, a frontwall, a connecting wall connected between the rearwall and the frontwall to define a chamber thereamong. The connecting wall has a rearwall-connecting portion connected to the rearwall, and a frontwall-connecting portion connected between the frontwall and the rearwall-connecting portion and having a thickness smaller than that of the rearwall-connecting portion so as to allow for floating movement of the frontwall relative to the rearwall.
