Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

Document And Entity Information - shares
3 Months Ended
Dec. 31, 2020
Feb. 11, 2021
Document And Entity Information    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Dec. 31, 2020  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q1  
Entity Registrant Name Arch Therapeutics, Inc.  
Title of 12(g) Security Common Stock, par value $0.001 per share  
Entity Central Index Key 0001537561  
Current Fiscal Year End Date --09-30  
Entity Current Reporting Status Yes  
Entity Filer Category Non-accelerated Filer  
Trading Symbol ARTH  
Entity Common Stock, Shares Outstanding   193,594,766
Entity Shell Company false  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Interactive Data Current Yes