Employing　the　nonequilibrium　Green＇s　function　technique,　electron　transport　characteristics　through　a　laterally　coupled　triple-quantum-dot　chain　are　investigated.　The　conductance　versus　electron　energy　is　numerically　calculated.　Two　anti-resonance　points　change　into　two　anti-resonance　bands　with　increasing　the　size　of　triple-quantum-dot　chain.　The　widths　of　two　anti-resonance　bands　are　the　same　and　can　be　regulated　via　adjusting　the　inter-dot　tunneling　coupling　strength　in　the　main　chain　or　its　attachment.　Spin-polarized　window　emerges　due　to　Zeeman　splitting　as　an　external　magnetic　flux　is　introduced.　Our　studies　demonstrate　that　the　system　can　be　used　as　a　quantum　switch　or　an　efficient　spin　filtering.