  We study the single production of scalar neutrinos or charginos via
$\gamma\gamma$ collision in an R-parity ($R_{p}$) violating supersymmetric
model. It may be possible to detect a sneutrino or a chargino at a Linear
Collider (LC) in $\gamma \gamma$ operation mode, as a test of supersymmetry and
$R_p$-violation. Because of the clean background in LC, stringent constraints
on $R_p$ violating parameters can be obtained even if the process cannot be
observed at the future Linear Collider.
