Axis.MinorTickMark (Excel)

Returns or sets the type of minor tick mark for the specified axis. Possible return values are xlTickMarkCross - Crosses the axis, xlTickMarkInside - Inside the axis, xlTickMarkNone - No mark, xlTickMarkOutside - Outside the axis.

XlTickMark can be one of the XlTickMark constants.

ActiveChart.Axes(1).MinorTickMark = xlTickMarkCross