A hole cover comprising: a tubular fitting member , to be fitted to a tubular portion of a rack housing which houses a pinion shaft which partially protrudes from the tubular portion , the hole cover , when fitted, covering the pinion shaft and a through hole of a dash panel (D) of a vehicle, the pinion shaft being inserted through the through hole; and an annular seal member disposed radially inward of the tubular fitting member , wherein the tubular fitting member includes: a cover-side fitting portion to be fitted to an outer periphery of a tubular housing-side fitting portion provided on the tubular portion ; a cover-side interposing portion configured to interpose the annular seal member in an axial direction between the cover-side interposing portion and a housing-side interposing portion provided on the tubular portion ; and a covering portion that covers an outer periphery of the annular seal member , and wherein the covering portion is provided with an opening passing in and out through the covering portion , characterized in that, the opening is provided so that the annular seal member is exposed to an outside in a state in which the fitting of the tubular fitting member to the tubular portion is completed, namely when a fitting length, which is a length of a part of the cover-side fitting portion that is fitted to the tubular housing-side fitting portion , is a predetermined fitting length, and in a state in which the rack housing is not mounted on a vehicle. a tubular fitting member , to be fitted to a tubular portion of a rack housing which houses a pinion shaft which partially protrudes from the tubular portion , the hole cover , when fitted, covering the pinion shaft and a through hole of a dash panel (D) of a vehicle, the pinion shaft being inserted through the through hole; and an annular seal member disposed radially inward of the tubular fitting member , wherein the tubular fitting member includes: a cover-side fitting portion to be fitted to an outer periphery of a tubular housing-side fitting portion provided on the tubular portion ; a cover-side interposing portion configured to interpose the annular seal member in an axial direction between the cover-side interposing portion and a housing-side interposing portion provided on the tubular portion ; and a covering portion that covers an outer periphery of the annular seal member , and wherein a cover-side fitting portion to be fitted to an outer periphery of a tubular housing-side fitting portion provided on the tubular portion ; a cover-side interposing portion configured to interpose the annular seal member in an axial direction between the cover-side interposing portion and a housing-side interposing portion provided on the tubular portion ; and a covering portion that covers an outer periphery of the annular seal member , and wherein the covering portion is provided with an opening passing in and out through the covering portion , characterized in that, the opening is provided so that the annular seal member is exposed to an outside in a state in which the fitting of the tubular fitting member to the tubular portion is completed, namely when a fitting length, which is a length of a part of the cover-side fitting portion that is fitted to the tubular housing-side fitting portion , is a predetermined fitting length, and in a state in which the rack housing is not mounted on a vehicle. <EOS>