PURPOSE: To eliminate the scattering of ink droplets being wiped off by a wiper piece, by differentiating the inclination of the wiper piece in the long side direction from the inclinations at both ends of the front surface of a printing head.

CONSTITUTION: The long side directions of wiper pieces 7, 8 are not at right angles to the moving direction c-c' of an ink head but inclined relative to said moving direction. As the printing head 1 advances to the d-direction, the wiper piece 8 is gradually spaced apart from the front surface of the printing head 1 from the upper side thereof. As mentioned above, because both ends of the printing head 1 are at right angles to the relative and straight moving direction of said head 1 while the long side directions of the wiper pieces 7, 8 are not right angles with respect to the moving direction, the front surface of the printing head is gradually separated from the wiper pieces when the front surface of the printing head and the wiper pieces are spaced apart while the wiper pieces are gradually restored and, therefore, ink droplets wipen off by the wiper pieces are not scattered. If the configurations at both ends of a printing head 1' are brought to straight lines in an oblique direction, the long side direction of each wiper piece may be at right angles with respect to the moving direction of said head 1'.