Background: In emergency departments, rapid screening of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important for arranging limited isolation resources and patient care during the coronavirus disease 2019 (COVID-19) pandemic. STANDARD M10 SARS-CoV-2 (SD Biosensor) is a recently developed cartridge-based RT-PCR that provides a turnaround time of 1 h, which is shorter than that for conventional RT-PCR. This study evaluated the clinical performance of STANDARD M10 in an emergency department. Methods: From March to June 2022, two pairs of nasopharyngeal and oropharyngeal swabs were collected from patients visiting an emergency department. Respective specimens underwent rapid RT-PCR using STANDARD M10 and conventional RT-PCR using Allplex SARS-CoV-2 (Seegene). When discordant results occurred, specimens undergoing the STANDARD M10 were retested with the Allplex to exclude specimen variations. Retest results replaced initial results of the Allplex. Clinical performance of STANDARD M10 was compared with Allplex. Results: The study enrolled 1,971 patients. COVID-19 prevalence was 6.2% based on the Allplex. Compared with the Allplex, overall agreement, positive percent agreement, and negative percent agreement of STANDARD M10 were 99.5% (95% CI: 99.1–99.8%), 95.9% (95% CI: 90.8–98.3%), and 99.8% (95% CI: 99.4–99.9%), respectively. Discordant results between STANDARD M10 and Allplex were observed only in specimens with Ct >33 using the Allplex. Conclusions: The STANDARD M10 showed reliable diagnostic performance for detecting SARS-CoV-2 in emergency departments and is a useful tool in emergency healthcare systems because of its easy-to-use cartridge-based assay and short resulting time for detecting SARS-CoV-2.