Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

Document And Entity Information - shares
6 Months Ended
Mar. 31, 2022
May 13, 2022
Document Information [Line Items]    
Entity Central Index Key 0001537561  
Entity Registrant Name Arch Therapeutics, Inc.  
Amendment Flag false  
Current Fiscal Year End Date --09-30  
Document Fiscal Period Focus Q2  
Document Fiscal Year Focus 2022  
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2022  
Document Transition Report false  
Entity File Number 000-54986  
Entity Incorporation, State or Country Code NV  
Entity Tax Identification Number 46-0524102  
Entity Address, Address Line One 235 Walnut Street, Suite 6  
Entity Address, City or Town Framingham  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 01702  
City Area Code 617  
Local Phone Number 431-2313  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   237,069,770