| abstract |
A recording unit is provided which includes an ink housing part for housing an ink containing a coloring material and an aqueous medium, and an ink jet head part for discharging an ink droplet of the ink, wherein at least one color of the ink is a polyvalent metal salt containing ink further containing a polyvalent metal salt; the ink jet head part for discharging at least the polyvalent metal salt containing ink has a configuration comprised of a substrate having on a base body, a heat-generating resistor member forming a heat-generating part, an electrode wire electrically connected to the heat-generating resistor member, and a cavitation resistant film provided on the heat-generating resistor member and the electrode wire via an insulating protection layer, and a liquid flow path communicating with a discharge port for discharging an ink droplet provided corresponding to the heat-generating part; and the cavitation resistant film includes a layer comprised of an amorphous alloy containing Ta and a layer comprised of an amorphous body of an amorphous alloy which is rich in Ta than the amorphous alloy containing Ta or a passive matter of the amorphous body provided on the layer comprised of the amorphous alloy containing Ta. |